Radio frequency identification (RFID) technology has become widely used in virtually every industry, including transportation, manufacturing, waste management, postal tracking, airline baggage reconciliation, and highway toll management. A typical RFID system includes RFID tags, an RFID reader having an antenna, and a computing device. The RFID reader includes a transmitter that may provide energy or information to the tags, and a receiver to receive identity and other information from the tags. The computing device processes the information obtained by the RFID reader. In general, the information received from the tags is specific to the particular application, but often provides identification for an item to which the tag is affixed, which may be a manufactured item, a vehicle, an animal or individual, or virtually any other tangible article. Additional data may also be provided for the article. The tag may be used during a manufacturing process, for example, to indicate a paint color of an automobile chassis during manufacturing or other useful information.
The transmitter outputs RF signals through the antenna to create an electromagnetic field that enables the tags to respond by modulating the received RF signal according to a pre-defined protocol. A conventional tag may be an “active” tag that includes an internal power source, or a “passive” tag that is energized by the field.
The computing device serves as an information management system by receiving the information from the RFID reader, and performing some action, such as updating a database or sounding an alarm. In addition, the computing device serves as a mechanism for writing data into the tags via the transmitter.
Handheld RFID readers provide a portable means of interrogating tags attached to articles. Often times multiple tagged items are co-mingled in close proximity, thereby requiring a user to orient the handheld reader with respect to a specific RFID tag in order to ensure that the response received is only from the specific tag that one seeks to interrogate.